Thank you for the answer.
I am afraid, I have not only understood half of it. Is there anywhere a tutorial for this elements?
I studied the turorial in the examples, but as far as I remember, such sophisticated details are not part of it.
I think, I want both:
Knowing the things, you mentioned in your posting for many purposes and use a filter for many purposes.
And I found in the fb-example a prefab SQL-query. Such queries shall give me search-results very nicely.
SQL requests are nice to debug as well as they give resulst on scratch.
btw datastore:
I cried of joy as I found in an example popup-menue "import ical" and I tried. It worked at sudden.
Is there a good way to encaplsula (can we say this?) such ical downloads and to import it as test?
The idea is, that such downloads from the internet may mess the whole database with unwanted verbose events.
My idea at them moment is:
Create a new ressource, import the ical there and delete the ressource as a bundle in the worst case.
Is this a good way?
The disadvantage is, that it is too tricky for a DAU like me in 2 years, who will not be able to remember this way any more.